Potential of natural regeneration of Quercus robur L. in floodplain forests in the southern part of the Czech Republic

Abstract

ABSTRACT:The most common way of pedunculate oak regeneration on the floodplain sites in the Czech Republic is artificial regeneration by clear-cutting. However, what is the real potential of natural regeneration of pedunculate oak? In our research object (3,355 ha of floodplain forest in the southern part of the Czech Republic -Zidlochovice region), we inventoried about 8 ha of successful natural regeneration of pedunculate oak with density ranging between 15,000 and 100,000 individuals per ha on the plots after final cut. All harvested oak dominated parent stands showed a lower stock density that ranged between 0.5 and 0.8. In the next analysis of the survival of oak natural regeneration spontaneously established in different light conditions under the shelter of parent stands we observed the highest occurrence of saplings closer to the forest edge. A sufficient density of regeneration (above 10,000 individuals per ha) was found at the distance up to 18 m from the edge, where more than 24% of direct and 30% of indirect site factor were discovered. In the stand with the full canopy closure (DSF about 10% on average and ISF about 24%) the oak regeneration is missing and was replaced by other tree species (especially ash and field maple). In the examined area the natural regeneration of pedunculate oak should be one of the possible alternatives of floodplain forest regeneration if certain conditions are met.

Main problems in natural seed regeneration of pedunculate oak (Quercus robur L.) stands in Ukraine

“…During the survey of 3,505 hectares of floodplain oak forests in the southern part of the Czech Republic, Dobrovolný (2014) found only 8 hectares of the area with sufficient natural reproduction of pedunculate oak of 15-100 thousand stems ha -1 after felling. The study of natural oak reproduction under the stand canopy in different lighting conditions has shown that the largest number of the reproduction (more than 10 thousand stems ha -1 ) was found near the forest margin at a distance of 18 m from the edge at the illumination of above 24%.…”

“…It will allow predicting their further development and preserving genetic potential. This problem becomes significant due to the current gradual warming and aridization of climate and the dynamic increase in the area of the nature reserve fund, the majority of which are tree stands with oak in their composition (Dobrowolska, 2008;Dobrovolný, 2014;Annighöfer et al, 2015;Tkach et al, 2017).…”

Ukrainian plain oak forests and their natural regeneration

“…The success rate of natural oak regeneration depends on many factors, such as the number of oaks in the stand and their age, the relative density of stocking, the acorn yield, sufficient heat, moisture, and light, and the development of shrub and grass layers (Vedmid et al, 2008;Kharchenko & Kharchenko, 2012;Ligot et al, 2013;Dobrovolný, 2014;Levchenko, 2014;Tkach et al, 2014;Annighoefer et al, 2015;Sendonin, 2015;Sevillano et al, 2016).…”

Surprinzătoarea simplitate a tratamentelor adecvate stejăretelor pure și amestecurilor cu stejar

“…Întreaga literatură consultată, atât din România (Drăcea 1920-1921, Negulescu și Săvulescu 1965, Haralamb 1967, Constantinescu 1973, Stănescu 1979, Stănescu et al 1997 2011), atât în tinerețe, cât și ca arbore adult. Acest fapt creează mari probleme pentru regenerarea naturală a speciei, deoarece exemplarele tinere rezistă sub masivul închis al arboretului doar 2-3 ani, apoi se autorecepează repetat, până se usucă definitiv (Petcuț 1942, Negulescu și Săvulescu 1965, Constantinescu 1973, Stănescu 1979, Stănescu et al 1997, Dobrovolný 2014. Aceasta face ca puieții de stejar să trebuiască a fi eliberați complet de acoperișul de sus sau lateral al arboretului parental după cel mult 4 (5) ani (Vlad 1954, în Vlad 2007, Haralamb 1967Boudru 1989).…”